1. Field of the Invention
This invention relates to a semiconductor device, particularly to a semiconductor device with a semiconductor die mounted on an external connection medium.
2. Description of the Related Art
Conventionally, a mold package formed by sealing a semiconductor die with a sealing member of epoxy resin and so on has been known as a packaging technology of a semiconductor die such as an IC (Integrated Circuit). In such a packaging technology, the semiconductor die is mounted on an island portion of a lead frame which is an external connection medium and connected with a lead terminal of the lead frame, before sealed with the sealing member. Next, a conventional semiconductor device with the semiconductor die mounted on the lead frame will be described with reference to drawings.
FIG. 5 is a schematic cross-sectional view of the conventional semiconductor device with the semiconductor die mounted on the lead frame. As shown in FIG. 5, pad electrodes 41 are formed on a front surface as a first surface of a semiconductor die 40 (e.g. IC). This semiconductor die 40 is mounted on an island portion 50isd of a lead frame 50. A back surface as a second surface of the semiconductor die 40 is attached to the island portion 50isd. Furthermore, the pad electrodes 41 of the semiconductor die 40 are electrically connected (i.e. bonded) with lead terminals 51 of the lead frame 50 through bonding wires 52 made of gold fine wires.
Although not shown, the lead frame 50 mounted with the semiconductor die 40 is sealed with a sealing member made of, for example, epoxy resin. The relevant technology is disclosed in Japanese Patent Application Publication No. Hei. 08-051179.
In the above semiconductor device, however, the pad electrodes 41 and the lead terminals 51 are connected with the bonding wires 52, causing such a problem that outside dimensions of the semiconductor device becomes large.
Furthermore, since the bonding wires 52 are fine, such a problem occurs that ON-resistance becomes high and high heat generation occurs when the semiconductor device mounted on a printed circuit board is in operation. This results in degradation of electrical characteristics of the semiconductor device.